Background: Atrial fibrillation (AF) has been associated with a poor prognosis in patients with ST-segment elevation myocardial infarction. There is considerable controversy regarding the prognostic implications of different types of AF.
Methods and results: We analyzed 913 patients consecutively admitted to our center with ST-segment elevation myocardial infarction undergoing a primary percutaneous coronary intervention. Clinical, ECG, and angiographic data were collected. We carried out univariate and multivariate analysis, using a combined endpoint of death, reinfarction, stroke, and clinically relevant bleeding. AF was documented in 117 patients. Among them, 25 presented AF at admission (previous AF) and 92 developed new-onset AF (66% transient, 13% persistent). Patients with AF were older, more frequently men, and had a worse Killip class, and a poorer left-ventricular ejection fraction. When analyzing the different types of AF, patients with new-onset AF (persistent and transient) had a higher Killip class and a worse left-ventricular ejection fraction. AF was associated with significantly higher in-hospital mortality and with a greater incidence of in-hospital adverse events. An increase in in-hospital mortality was recorded both for previous and for new-persistent AF, but after adjusting for confounding factors, only persistent AF was found to carry a worse short-term prognosis.
Conclusion: In patients undergoing primary angioplasty in the stent era, AF is associated with a poor prognosis. This risk appears to be particularly high among patients with persistent AF.